The 11 Best Diets for Fast Weight Loss

Does bikini season sneak up on you each summer? Is your soon-to-be worn wedding dress still just a touch too tight? Were your holiday outfits uncomfortably snug? Did a last-minute invite for a beach getaway come your way? You’re a lucky dog – and a panicked one too because you want to drop pounds, and fast. These 11 diets are likely to help you lose significant weight within a year, according to a panel of experts who reviewed 39 plans for the U.S. News Best Diets rankings. Just remember: Short-term weight loss is markedly different from long-term weight loss, which is more important for your health.

The HMR Program (Health Management Resources Program) uses meal replacements – think low-calorie shakes, meals, nutrition bars and hot cereal – in phases, coaching from experts, physical activity and an emphasis on fruits and vegetables to help dieters shed pounds fast. For the third straight year, the diet has the No. 1 ranking to itself. “This diet makes it easy to lose weight fast and would likely be effective for someone who wants to lose weight for a specific event,” one expert says. “However, as far as long-term healthy-habit-forming, this diet falls short” in part because dieters don’t learn to make their own healthy food choices.

A large part of the appeal of the Atkins Diet, which aims to burn fat by limiting carbs and packing in fat and protein, is its claim of quick weight loss – as much as 15 pounds in two weeks, according to the company. Our experts agreed that’s a legitimate pitch, but note that much of the initial weight loss is water, due to the diet’s diuretic effect. “That means that the short-term weight loss looks much better than it really is, and when you stop the program, all the water comes back on,” one expert pointed out.

WW (formerly Weight Watchers) – a plan that uses a point system to encourage followers to choose healthy, filling foods – claims you can shed up to 2 pounds a week. Our experts back its ability to deliver quick results. Better yet? Those results are likely to last, thanks to the program’s emphasis on a balanced diet with no restrictions, as well as its built-in support system. “This is a tried-and-true plan with a proven track record, plus tools and support to help people succeed,” one expert concludes. Why not prepare for next bikini season as well?

If you ever saw the TV show, you get the idea: Six weeks of healthy food and regular exercise is celebrated as a great start to a weight-loss journey – as well as a way to prevent or reverse various diseases. Fair enough. Experts determined that the Biggest Loser Diet is very likely to help you shed pounds, thanks to calorie restriction and exercise. But a 2016 study suggested the diet can lead to a permanent dip in metabolism, and experts also worry that the exercise guidance – as much as three hours a day – is excessive and a lot harder for average Joes than for TV stars-in-the-making.

Butter, bacon, burgers, oh my! Meals consisting of high-fat foods like these are hallmarks of the keto diet, an extremely low-carb, high-fat plan that aims to send you into ketosis, a state in which your body is forced to burn fat, not sugar, for energy. Though quick weight loss is indeed likely on the keto diet, experts don’t recommend it for most people since it lacks nutritional variety and is unsustainable long term. As one expert puts it: “It is a rigid diet, it is not environmentally friendly and we don’t have epidemiological evidence of populations eating this way.” In other words: Follow at your own risk.

OPTAVIA, a brand from the team behind Medifast, is bound to lead to weight loss in most adults. After all, you’ll likely be limited to 1,000 calories a day coming from one daily meal and five 100-calorie “fuelings,” whether shakes, bars, eggs, oatmeal, pancakes, pudding, soup, brownies or even cheese puffs. But don’t expect to stay on this plan longer-term: One U.S. News expert calls the products “unpalatable” and, on the whole, OPTAVIA ranked less-than-optimally on metrics like safety and nutrition.

Jenny Craig’s prepackaged meals and recipes help participants lose weight – up to 2 pounds a week, it says – through restricting calories, fat and portions. One 2015 review of studies suggests it works: It found that participants lost more weight in a year on the plan than on other commercial weight-loss programs, including WW (formerly Weight Watchers), Nutrisystem and Medifast. Experts deemed Jenny Craig “very effective” for short-term weight loss, some praising its focus on teaching proper portion sizes and helping dieters learn to eat when they’re hungry, rather than when they’re bored or emotional.

Nutrisystem is safe and easier to follow than many other diets, according to experts. The pre-portioned, low-calorie meals may make Nutrisystem particularly helpful in early dieting. “Packaged foods can becoming boring after so many months, but at least it takes the decision out of, ‘What do I eat today?'” an expert notes. Another pro’s take: “I recommend it to those who are not fond of cooking and don’t care about eating fresh foods. I wouldn’t recommend it to those who love to eat fresh foods.”

The Raw Food diet earns solid marks for weight loss. But it’s considered all but impossible to follow. In addition, its nutritional completeness and safety are questioned by experts who raise concerns about the potential for food poisoning from contaminated ingredients that are raw or undercooked.

“More research is needed on the raw foods approach,” one expert says. “I believe it may have tremendous health benefits and may help protect against heart disease, diabetes and related health problems. Unfortunately it is very hard to follow, and we don’t know enough about how to use the raw foods approach safely.” Another reviewer harrumphs: “Lots of unnecessary rules,” “based on false assumptions,” “silly, actually” and “I can’t imagine sticking to this long term, nor would I want anyone to.”

SlimFast is designed to make cutting calories simple and fast weight loss likely, with products like shakes, smoothies and meal bars replacing two meals a day and snacks. “Meal replacements are supported in studies to help promote weight loss and weight maintenance,” one U.S. News expert said. But as with most diets that do well in the fast weight-loss category, SlimFast lacked in other departments, like heart health and sustainability. If you’re aiming to lose more than 20 pounds (which should take about 10 weeks on this plan), SlimFast may not be your best bet.

By filling up on bulky foods with few calories (think carrot sticks rather than cashews), as the Volumetrics Diet dictates, you’re likely to lose significant weight during the first year, experts said (1 to 2 pounds per week to be exact, according to the company). The plan is praised for teaching dieters portion control and how to choose foods that are low in calories but keep you feeling fuller longer. It’s also a “different and effective approach that is uncomplicated and flexible – what most people need to stay with any eating plan,” one pro said.

• HMR Program.
• Atkins Diet.
• WW (formerly Weight Watchers) Diet.
• Biggest Loser Diet
• Keto Diet.
• OPTAVIA Diet.
• Jenny Craig Diet.
• Nutrisystem Diet.
• Raw Food Diet.
• SlimFast.
• Volumetrics Diet.